A 2014 study found the cold not only makes brown fat more active, it also could cause you to grown more brown-fat cells.

“Browning fat tissue would be an excellent defense against obesity. It would result in the body burning extra calories rather than converting them into additional fat tissue,” Philip A. Kern, who authored the study, said in a release.

“Similarly to exercise training, we advocate temperature training,” the researchers said. “More-frequent cold exposure alone will not save the world, but is a serious factor to consider in creating a sustainable environment together with a healthy lifestyle.”

Boost vitamin D and combat SAD

The shorter days of winter and lower temperatures can contribute not only to vitamin D deficiencies, but also to developing seasonal affective disorder.

One recommendation to treat SAD is a light therapy box, which mimics sunlight. But light boxes can’t boost your vitamin D intake. Exercising outdoors, even if it’s just going for a walk, can serve both the vitamin and fitness boost.